| Using satellite data and NCEP/NCAR 1 1 reanalysis data, series of studies, from the viewpoint of satellite meteorology, are finished on mesoscale convective systems (MCS) and their possible genesis and evolution mechanism in the Meiyu front. These works include the cloud system families of the Meiyu heavy rainfall and their interactions, the structure, precipitation characteristics and microphysical features of the mesoscale convective complexes (MCC), the favorable genesis and evolution settings for MCS, the different environments between MCC and meso-p-scale convective system, the relationship between the tropical water vapor plume (WVP) and MCS, and what characteristics of the WVP. Also the scale-separated technique is introduced to depict the clear mesoscale structure with the MCS, and the isentropic potential vorticity (IPV) and the moist potential vorticity (MPV) are used to diagnose the evolution mechanism of MCS. Finally the powerful MM5 modeling system is run to help better understanding the initiation of MCS, as well as its dynamic and thermodynamic structures.Following are the investigations made in these studies and findings. The typical cloud system families of the Meiyu heavy rainfall are the Meiyu front cloudsystem, the westerly short wave trough cloud system, the cloud system from the eastern Tibetan plateau and the monsoon cloud clusters. Their interactions are important for the Meiyu cloud system's construction/reconstruction to form a specific cloud style and intensity. The families are corresponded to synoptic systems, also are results of their interactions. In fact, the subtropical high affects the position of the Meiyu cloud system so that the region of heavy rainfall determined. The mid-level short wave trough could induce cyclone in the Meiyu front to produce associated heavy rainfall. When leading by the traveling short wave trough, the cloud system in the eastern Tibetan plateau could move eastward. Then the south-west cyclone follows from the Sichuan Basin to produce heavy rainfall on the way. Though the monsoon cloud clusters are not often to go across the east foot of the Tibetan plateau to the lower reaches of the Changjiang River Basin, they could touch the Meiyu cloud system whenever the subtropical high retreating eastward, hence heavy rainfall comes. The TBB (Black-Body Temperature) analysis depicts that several meso-p-scale cloud clustersand convective cells are embedded and alternately developed within a MCC. As the strongest convection gradually decrease, the cold TBB area expand quickly in hours before dissipation. However, the heavy rainfall occurs in MCC's developing and maturing stages. And the minimum TBB fluctuation matches well to the precipitation trend (the lower TBB the heavier rainfall). The cloud top properties and cloud phase show that MCC develops in a broad water cloud area with multi-layer cloud, density ice cloud, and cirrus cloud consisted. The heaviest hourly rainfall orients to the density ice cloud portion where ice cloud become turn to be water cloud. The hydrometeors distribution in MCC illustrat that the precipitable ice is dominant which fills in the cloud cluster in almost entire troposphere with maximum cores at the mid-levels. Rain water and cloud liquid water are in the middle and lower troposphere, and cloud ice water only scatters at the 8-18km upper levels. The hydrometeor maxima extend over the location where the convection is most active, therefore hydrometeors transformation in condensation/sublimation processes are frequent. The satellite analysis confirms the MCS with certain mesoscale anomalies that revealed byscale-separated technique introduced by Xia Daqing (1983). The mesoscale systems have closed relationship to the - 52 TBB region with convergence in the lower levels however divergence in the upper levels. The different organizing of mesoscale cyclone and "convective line" makes the MCSs difference in shapes with circular or belt, respectively. A kind of favorable synoptic environment for Ma...
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